This application relates generally to communication systems, and, more particularly, to wireless communication systems.
Wireless communication systems include a network of devices for providing wireless connectivity to wireless-enabled devices including mobile units, smart phones, tablet devices, laptops, desktops, and other types of user equipment. The network access devices include base stations, base station routers, access points, e-node-Bs (eNBs), and the like. The entities within the wireless communication system generally conform to standards and/or protocols that facilitate communication over the air interface. For example, wireless communication systems are currently being developed that operate according to the Long Term Evolution (LTE) standards and/or protocols defined by the Third Generation Partnership Project (3GPP, 3GPP2). The LTE-Advanced standard supports both frequency division duplexing (FDD) and time division duplexing (TDD). Service providers are expected to implement both types of systems depending on the circumstances of the deployment scenario. The advantages to deploying a TDD system include efficient use of the radio spectrum because TDD uses a single frequency resource and does not require the paired set of frequency resources used to implement FDD.
Interference between neighboring base stations and/or user equipment can reduce the benefits of resource sharing in a TDD system. For example, base-station-to-base-station (BS-to-BS) interference occurs when one base station transmits a downlink signal to user equipment in a subframe while another base station is attempting to receive an uplink signal from other user equipment during the same subframe. For another example, user-equipment-to-user-equipment (UE-to-UE) interference occurs when one or more user equipment are transmitting uplink signals in a subframe while other user equipment are trying to receive downlink signals in the same subframe.